游标卡尺在工程上是一件最常用的长度测量器具．这种仪器的工作原理和读数方法多数学生很难熟练掌握，为了讲述仪器的工作原理和读数方法，教师要在黑板上画图，要画出一个十分游标的正确板图已经十分困难，绘制五十分游标是不可能的．用教学模型也只有将近１ｍ长的十分游... Vernier caliper is one of the most commonly used length measuring instruments in engineering. The working principle and reading method of this kind of instrument are hard to master by most students. To tell the working principle and reading method of the instrument, the teacher wants to draw the picture on the blackboard. It is already very difficult to draw a correct cursive correct board and draw fifty Points cursor is impossible. With the teaching model is only about 1m long very tour ...